1. Field of the Invention
This invention generally relates to a therapeutic ultrasound method and system, and more particularly, to a method and system for ultrasound treatment for superficial tissue containing sweat glands.
2. Description of the Related Art
The sweat glands in the body are of divided into apocrine and eccrine glands. Apocrine glands are similar to sebaceous glands, and are present mainly in the axillae. These glands, like sebaceous glands, secrete an oily proteinaceous product into the follicles. Bacterial digestion of apocrine sweat is largely responsible for underarm “body odor”. Similarly, eccrine sweat glands are present deep in the dermis in the palms, soles and armpits and are responsible for temperature regulation resulting from sweating. Excessive activity of these glands also results in copious amounts of abnormal sweating (“hyperhidrosis”), primarily under autonomic neuronal control. Reduction of sweating from under the armpits and other regions is a particularly desirable effect within the modern society. Presently, chemical antiperspirants and deodorants are used frequently as a matter of personal hygiene. Antiperspirants are aluminum based salts that block the sweat gland ducts. The deodorant changes the pH of the skin milieu thereby minimizing the presence of (smell inducing) bacteria. The effects with both these components however, are temporary and these chemicals are known to irritate the skin in a good percentage of users.
Further, there is currently a significant unmet need in managing the excessive sweating and concomitant issues with odor as a result of Hydradenitis suppurativa (irritable infected armpit). This acne-like process in apocine follicles also causes hydradenitis suppurativa, which is often a devastating condition in which very painful cysts and scarring occurs repeatedly in the axillae. The etiology (causes) of this clinical condition is not well understood. However, there are a number of marginally effective approaches to manage this condition. Retinoid drug therapy works marginally but is associated with severe toxicity. Some prescription formulations of antiperspirants can be used, but they are not particularly effective. These preparations can be applied with the addition of an iontophoretic device. This technique however, is not known to be any more effective than the formulation. The sweat glands can be surgically removed from the armpits and/or the sympathetic nerve supply can be interrupted surgically. This approach is fraught with its own drawbacks in terms of morbidity, scarring and cost. BOTOX® is being used ever more for paralyzing the nerve connections that induce excessive sweating in the armpits. However, this is a new approach yet to be completely validated. This technique requires multiple injections (painful) and the results last a few months only (3-4 months), hence need to be repeated. This technique does not get rid of the odor associated with the condition.